Polymerization of isobutylene with an aluminum-titanium dioxide-titanium tetrachloride catalyst



l lowed to react within the 1 it 3,166,545 POLYMERIZATION F ISOBUTYLENE WITH AN ALUMINUM TITANIUM DIOXIDE TITANIUM TETRACHLORIDE CATALYST V 7 George FwPezdii-tz,"Hampton,\Va., assignor'to Texaco Inc., New York, N-Y a jcorporation of Delaware N0 Drawing. Filed Apr. 6, 1961, Ser.

Claims c1. zoo-44.3

This invention relatesto the catalytic polymerization of isobutylene. its more specific aspect, this invention relates to an improved catalyst adapted for use in the polymerization of isobutylene, and to the method of making such catalyst. l

The polymerization of unsaturated aliphatic hydrocarbons, such as olefins or mixtures thereof with a suitable catalytic material to form compounds of higher molecular weight is well known. However, in the polymerization of isobutylene employing known catalyst, such as BF it often is not possible-to obtain high molecular weight polymers. This invention has therefore as its purpose to provide for a new and improved catalyst for the polymerization of isobutylene tohigh molecular weight polymers, particularly higher molecular weight polymers heretofore not readily obtainable was knowncatalyst materials, and to the method of making-the catalyst.

In general, the polymerization catalyst of. our inven- United Stat Pace/t fifice tion comprises the product resulting from the reaction between aluminum, a titanium halide andtitanium dioxide. The. olefinic feed charge is contacted withthe resulting catalyst material under polymerization conditions, and the, higher molecular weightpolymer product is recovered fromthe reaction. The solid'catalyst material may be separated from the polymer product by conventional means. such as filtering,centrifuging or the like. The polymerization reactionemployingour inventive process is readily adaptable to a wide range of operat- 1 ing conditions, but the reaction conditions: depend to a large extent uponthe character of the polymer sought and the specific composition of the catalyst, as described hereinafter in greater detail.

phase or liquid phase. 'tageous and convenient to conduct the polymerization in Patented Jan. 19, 1965 'ly'st to aluminum can be varied, and may range from about 0.25 mol to about 5 molsof titanium per one mo of aluminum. More preferably, titanium is employed in proportions between about 0.5 mol to 2 mols per mol o'f'aluminurn. Generally the titanium content is between about 20 to 50 weight percent of the total catalyst.

Isobutylene may be polymerized in accordance with the present invention using our catalyst ineither the gas Generally, it is more advana liquid phase operation because the reaction conditions are more easily controlled and the activity of the catalyst is not as readily diminished as in gas operations. In conducting the polymerization under a liquid phase, it is often desirable to employ a solvent or diluent for the feed stock which provides an inert liquid reaction medium for the polymerization reaction. A saturated'hydrocarbon may be suitably employed as the solvent or diluent, and includes, for example, pentanes, hexancs, heptanes, etc. The solution of isobutylene prepared in the desired diluent may then be readily contacted with the polymerization catalyst.

The polymerization process may occur over a rather wide temperature range, but is generally conducted at a temperature of from about 100 F. to 200 F., and more preferably within a range of 40 F. to 150 F. Although higher pressures favor the polymerization reaction, relatively low pressures. can be employed in the process which may include, under suitable conditions,

pressures as low as atmospheric pressure or lower. How- The catalyst of our invention is prepared by reacting together an admixture'of aluminum, a titanium halide, elevated temperature and in. the presence of an inert gas. The temperature for car- .of the catalyst-is F., and more and titanium dioxide at an rying out the reaction in preparation in the range of from about 600 to1400 preferably 800 to 900 F. The components are alhour to 1 /2 hours, and in any event for a sufiicient length .of time to allow all thecomponents to react. The reacnitrogen. I p

r In the preferred embodiment of the present invention,

tion is carried out in aninert atmosphere, for example the titanium halide is in its highest valence state, and readily reduced to a relatively lower.

ture and exhibits high catalytic activity and therefore is particularly useful in the preparation of the catalyst. In the *p'refe'r'redmethod for preparing the catalyst, the

aluminum and titanium dioxide are mixed together'in the desired proportions and heated to an elevated temperature and. for a 'period of --time withinthe above described ranges.:. Upon addition of the required amountv of tidesired catalyst offhighactivity.

The proportion of totaltitanium employed in the cata- V desired temperature range for Y about 15 minutes to 3 hours, preferably for about /2 tanium tetrachloride to the'heated mixture, an exothermic reaction occurs, therebyJreSuIting in the formation of the. 0'

boas high as 200 p.s.i.g., or higher. A generally useful and desirable Fp ressuIerange is between about 0 p.s.i.g. and '60 p.s.i.g., preferably between about 0 p.s.i.g. and t "40 p.s.i.g. The contact time or space velocity employed 'in the polymerization process will be selected with reference to the other process conditions, and catalyst. A

suitable liquid hourly space velocity may range from about 0.2 to 5.0 v./hr./v., preferably from about 0.5 to 2.0 -v./ hr./v., but may be varied to obtain the desired results. Thus, it should be understood that the various operating conditions for the process may be varied over.

a wide range, and depends to some extent upon the cata- I lyst employed and-the ,end, product desired. However,

these optimurnco'nditions can be readily ascertained by experimentation by one skilled in'the art.

The polymers produced in the catalyst polymeriza-' tion of our process havemany useful applications. These may include the production of synthesis of valuable or- .ganic chemicals, resins, plastics, etc. In addition, it is possible to produce polymers .in the viscosity range of lubricating oils, or the polymers may be used in other applications where olefin derivatives are desired.

The following example further illustrates the catalytic polymerization of our invention.

v The catalyst was prepared by initially mixing together 0.4 mol aluminum powder and 0.25 mol of titanium dioxide, and heating the mixture to 842 F. for one hour in a nitrogen atmosphere. To this hot mixture was added 0.05 mol of titanium tetrachloride, and an exothermic reaction occurred, resulting in the formation of a black powder. I

Two grams of catalyst prepared from thereaction was placed in a tube, and grains of isobutylene dissolved in 100 mol of heptane as a diluent was added to the tube. The polymerization reaction was allowed to proceed for A total volume of 46.2 grams of polymer wascollected,

thepolymer having a viscosity average molecularweight;

2 hours at 14 F. temperature andatmospheric pressure.

form higher molecular weight polymers thereof which comprises contacting said isobutylene in an inert liquid reaction medium under polymerization conditions including a temperature in the range of from about -100 F. to 200 F. and under a pressure of from about 0 p.s.i.g. to 200 p.s. i.g. with a polymerization catalyst prepared by mixing together aluminum and titanium dioxide at a temperature of from about 600 F. to 1400" F. and for a time from about 15 minutes to 3 hours, and adding titanium tetrachloride to said heated mixture, the molar ratio of total titanium to aluminum in said catalyst being about 0.25 to 5 mols of titanium to- 1 mol of aluminum.

2. A process according to claim 1 in which the molar ratio of said titanium to aluminum in said catalyst is from about 0.5 to 2 mols of titanium to 1 mol of aluminum.

3. A process for preparing a catalyst for the polymeriza tion of isobutylene which comprises mixing together aluminum and titanium dioxide at a temperature of from about 600 F.'to 1400 F. and for a time of from about 15 minutes to 3 hours, and adding titanium tetrachloride to said heated mixture, the molar ratio of total titanium to aluminum in said catalyst being about 0.25 to 5 mols of titanium to 1 mol of aluminum.

4. The process according to claim 3 wherein the molar ratio of total titanium to aluminum in said catalyst is from about 0.5 to 2 mols of titanium to 1 mol of aluminum.

5. The process according toclaim 3 wherein said temperature for said reaction is from 800 F. to 900 F., and said time for said reaction is /2 hour to 1 /2 hours.

References Cited in the file of this patent UNITED STATES PATENTS 2,928,818 Carter et a1 Mar. 15, 1960 3,008,943 Guyer Nov. 14, 1961 3,010,787 Tornqvist Nov. 28, 1961 

1. A PROCESS FOR THE POLYMERIZATION OF ISOBUTYLENE TO FORM HIGER MOLECULAR WEIGHT POLYMERS THEREOF WHICH COMPRISES CONTACTING SAID ISOBUTYLENE IN AN INERT LIQUID REACTION MEDIUM UNDER POLYMERIZATION CONDITIONS INCLUDING A TEMPERATURE IN THE RANGE OF FROM ABOUT -100*F. TO 200*F., AND UNDER A PRESSURE OF FROM ABOUT 0 P.S.I.G. TO 200 P.S.I.G. WITH A POLYMERIZATION CATALYST PREPARED BY MIXING TOGETHER ALUMINUM AND TITANIUM DIOXIDE AT A TEMPERATURE OF FROM ABOUT 600*F. TO 1400*F. AND FOR A TIME FROM ABOUT 15 MINUTES TO 3 HOURS, AND ADDING TITANIUM TETRACHLORIDE TO SAID HEATED MIXTURE, THE MOLAR RATIO OF TOTAL TITANIUM TO ALUMINUM IN SAID CATALYST BEING ABOUT 0.25 TO 5 MOLS OF TITANIUM TO 1 MOL OF ALUMINUM. 